Once you have copied a Google Form to your Google Docs, you may edit it.
Open the Sheet that you copied.
Click Form > Edit form.
This opens the form in a separate window for editing.
Edit Form Name: Click the form name (upper left side). You many rename it by typing here.
Edit Questions:
To edit questions, select the questions tab at the top of the form, then click the six dots that appear when you hover your mouse over a question.